[TeMPOraL]

> This alone wouldn't prove that their hands are clean, just that they wouldn't be as much to blame as someone who didn't succumb to social pressures and had more of a choice in the matter.

I don't think this is the real deal behind that decision. We've established that people are generally pretty susceptible to authority and peer pressure. Moreover, military training exists primarily to increase it. But the effect that legal clause has is that it counteracts this susceptibility by removing any doubt you could have that you'll be on the hook if you follow orders telling you to commit atrocities. It reduces the effect of peer pressure.